Hi
Tiday i purchased my first EDF motor .... on the box it is mentioned that the maximum thrust is 90gr ..... i wonder what could be the all up weight of my airplane ?

You need to know the cubic loading, which becomes more important as you go smaller, as there is generally less leeway. I built and flew a 33" span airliner at over 11oz AUW with around that level of thrust. It was just amply powered. As you go smaller in span and wing area, the allowed AUW will decrease rapidly. For a reasonable level of assurance it's good to find something close to what you plan to build that successfully flew, look at the specs, and achieve those specs or better.

Originally Posted by AntiArf

You need to know the cubic loading, which becomes more important as you go smaller, as there is generally less leeway. I built and flew a 33" span airliner at over 11oz AUW with around that level of thrust. It was just amply powered. As you go smaller in span and wing area, the allowed AUW will decrease rapidly. For a reasonable level of assurance it's good to find something close to what you plan to build that successfully flew, look at the specs, and achieve those specs or better.

Sorry ... what AUW stands for ? Is it all up weight ?
If i build a model with proper wing loading or cubic liading can i fly a 200 gr model with this motor ?
Sorry for my english

Yes you can fly 200 grams. But less is better

As Turbonut said, less is probably better. Built 3 jets recently in the 8oz range, but 2 are are powered by 40mm EDFs, one a twin 30mm EDF, and they are 24" span. Chances are whatever you would build with a 30mm EDF would have less span/wing area and would be better to be lighter. The Sncaso is 8.3oz, likely having thrust in the 90gm range, given the losses. Again though it has reasonable wing loading and span at 24". It would probably not fly well, or even fly at all, if much heavier or smaller.
https://www.rcgroups.com/forums/show...n-Flight-Video

Another thing is even though something heavier may fly, it's nice to fly small models that can launch/land easily, and fly reasonably slow/handle well. The HK Electrolyte is not my kind of thing.

Thanks to everyone

You can build a relatively big plane with a relatively small edf but you will end up with a powered glider if you take it too far. The other way around a small plane with a big edf will be fast and more like a jet. Get the balance right with wing area, power and AUW, that's the key to a good jet model, but the smaller the model, the harder it is to make it work.

Originally Posted by FANtastic

You can build a relatively big plane with a relatively small edf but you will end up with a powered glider if you take it too far. The other way around a small plane with a big edf will be fast and more like a jet. Get the balance right with wing area, power and AUW, that's the key to a good jet model, but the smaller the model, the harder it is to make it work.

Want to design a plane for it .... despite the fact that i have no experience with the EDF .... and this is what makes my project more adventurous